Neves Marco Aurelio Invaldi, Pinfildi Carlos Eduardo, Wood Viviane Timm, Gobbato Rafael Corrêa, da Silva Fabio Mendes, Parizotto Nivaldo Antônio, Hochman Bernardo, Ferreira Lydia Masako
Department of Plastic Surgery, Universidade Federal de São Paulo, Rua Napoleão de Barros 715, São Paulo, Brazil.
Photomed Laser Surg. 2011 Oct;29(10):663-8. doi: 10.1089/pho.2010.2919. Epub 2011 Jun 13.
The purpose of this study was to evaluate the effect of an 830-nm GaAlAs diode laser operating at output powers of 40, 60, 80, and 100 mW and energy density of 30 J/cm(2) on the repair of partial calcaneal tendon ruptures in rats.
A partial tendon rupture was induced in all animals, which were treated with laser irradiation for 5 consecutive days. Six days after injury, the injured tendons were removed and examined by polarized light microscopy. Collagen fiber organization was evaluated by birefringence measurements, and collagen content was determined by Picrosirius Red staining.
It was observed that the higher the output power (60-100 mW) the greater the amount of type III collagen (p<0.01). The amount of type I collagen was significantly greater (p=0.05) in the 80 mW group than in the control group (sham stimulation). A non-statistically significant improvement in the realignment of collagen fibers was observed in the irradiated groups.
Low-level laser therapy resulted in significantly greater amounts of type III collagen (output powers of 60 mW or more) and type I collagen (output power of 80 mW), however, no significant differences between groups were found in the realignment of collagen fibers.
本研究旨在评估波长830 nm的砷化镓铝二极管激光，在输出功率分别为40、60、80和100 mW且能量密度为30 J/cm²时，对大鼠跟腱部分断裂修复的影响。
诱导所有动物造成跟腱部分断裂，连续5天用激光照射进行治疗。损伤6天后，取出损伤的跟腱，用偏振光显微镜检查。通过双折射测量评估胶原纤维组织，用天狼星红染色法测定胶原含量。
观察到输出功率越高（60 - 100 mW），III型胶原量越多（p < 0.01）。80 mW组的I型胶原量显著多于对照组（假刺激）（p = 0.05）。在照射组中观察到胶原纤维排列的改善，但无统计学意义。
低强度激光治疗导致III型胶原（输出功率60 mW及以上）和I型胶原（输出功率80 mW）量显著增加，然而，各组之间在胶原纤维排列方面未发现显著差异。
